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91.
Three‐dimensional direct numerical simulation results of flow past a circular cylinder are influenced by numerical aspects, for example the spanwise domain length and the lateral boundary condition adopted for the simulation. It is found that inappropriate numerical set‐up, which restricts the development of intrinsic wake structure, leads to an over‐prediction of the onset point of the secondary wake instability (Recr). A best practice of the numerical set‐up is presented for the accurate prediction of Recr by direct numerical simulation while minimizing the computational cost. The cylinder span length should be chosen on the basis of the intrinsic wavelength of the wake structure to be simulated, whereas a long span length is not necessary. For the wake transitions above Recr, because the wake structures no longer follow particular wavelengths but become disordered and chaotic, a span length of more than 10 cylinder diameters (approximately three times the intrinsic wavelength) is recommended for the simulations to obtain wake structures and hydrodynamic forces that are not strongly restricted by the numerical set‐up. The performances of the periodic and symmetry lateral boundary conditions are compared and discussed. The symmetry boundary condition is recommended for predicting Recr, while the periodic boundary condition is recommended for simulating the wake structures above Recr. The general conclusions drawn through a circular cylinder are expected to be applicable to other bluff body configurations. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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Dr. Yukun Zhu Chunxiao Lv Zhuocheng Yin Prof. Jun Ren Prof. Xianfeng Yang Prof. Chung-Li Dong Prof. Hongwei Liu Dr. Rongsheng Cai Yu-Cheng Huang Prof. Wolfgang Theis Prof. Shaohua Shen Prof. Dongjiang Yang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(2):878-883
Red phosphorus is a promising photocatalyst with wide visible-light absorption up to 700 nm, but the fast charge recombination limits its photocatalytic hydrogen evolution reaction (HER) activity. Now, [001]-oriented Hittorf's phosphorus (HP) nanorods were successfully grown on polymeric carbon nitride (PCN) by a chemical vapor deposition strategy. Compared with the bare PCN and HP, the optimized PCN@HP hybrid exhibited a significantly enhanced photocatalytic activity, with HER rates reaching 33.2 and 17.5 μmol h−1 from pure water under simulated solar light and visible light irradiation, respectively. It was theoretically and experimentally indicated that the strong electronic coupling between PCN and [001]-oriented HP nanorods gave rise to the enhanced visible light absorption and the greatly accelerated photoinduced electron–hole separation and transfer, which benefited the photocatalytic HER performance. 相似文献
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Yuxin An Qian Li Jiejun Chen Xiaokang Gao Hongwei Chen Chaoni Xiao Liujiao Bian Jianbin Zheng Xinfeng Zhao Xiaohui Zheng 《Biomedical chromatography : BMC》2014,28(12):1881-1886
A new mathematical model and frontal analysis were used to characterize the binding behavior of caffeic acid to human serum albumin (HSA) based on high‐performance affinity chromatography. The experiments were carried out by injecting various mole amounts of the drug onto an immobilized HSA column. They indicated that caffeic acid has only one type of binding site to HSA on which the association constant was 2.75 × 104/m . The number of the binding site involving the interaction between caffeic acid and HSA was 69 nm . The data obtained by the frontal analysis appeared to present the same results for both the association constant and the number of binding sites. This new model based on the relationship between the mole amounts of injection and capacity factors assists understanding of drug–protein interaction. The proposed model also has the advantages of ligand saving and rapid operation. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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We propose a new general type of splitting methods for accretive operators in Banach spaces. We then give the sufficient conditions to guarantee the strong convergence. In the last section, we apply our results to the minimization optimization problem and the linear inverse problem including the numerical examples. 相似文献
98.
Zhen-Su She 《中国科学:物理学 力学 天文学(英文版)》2018,(9)
正Newton’s gravitational law and its derived Kapler’s orbit of planetary motions are the very first triumph of science,which confirms that a purely human’s invention of mathematics is able to accurately describe observations in nature.For the 相似文献
99.
Cephalotanins A–D,Four Norditerpenoids Represent Three Highly Rigid Carbon Skeletons from Cephalotaxus sinensis 下载免费PDF全文
Dr. Jin‐Biao Xu Dr. Yao‐Yue Fan Prof. Dr. Li‐She Gan Dr. Yu‐Bo Zhou Prof. Dr. Jia Li Prof. Dr. Jian‐Min Yue 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(41):14648-14654
Four polycyclic norditerpenoids, cephalotanins A–D ( 1 – 4 ) representing three unprecedented carbon skeletons with highly rigid ring systems, were isolated from Cephalotaxus sinensis and structurally characterized by a combination of various methods. Compounds 1 and 2 are new skeletal norditerpenoid trilactones, while 3 and 4 are two norditerpenoids featuring different new carbon skeletons. Biosynthetic pathways for 1 – 4 were proposed by involving diverse and very fascinating chemical events with the coexisting cephalotane troponoids as the precursors. Compound 1 exhibited good NF‐κB inhibition with an IC50 value of 4.12±0.61 μΜ. 相似文献
100.
This paper studies eigenvalues of the drifting Laplacian on compact Riemannian manifolds with boundary (possibly empty) and provides a general inequality for them. Using the general inequality, we obtain universal inequalities for eigenvalues of the drifting Laplacian of Payne-Pólya-Weinberger-Yang type for manifolds supporting some special functions. We also obtain a lower bound for the first eigenvalue of the square of the drifting Laplacian on compact manifolds with boundary under some condition on the Bakry-Ricci curvature. 相似文献